Insulating head for electric cables under high pressure



May 30, 1950 G. POUZET 2,509,523

INSULATING HEAD FOR ELECTRIC CABLES UNDER HIGH-PRESSURE Filed April 27, 1946 2 Sheets-Sheet l En -l.

HIGH PREJSl/R f FL U/Q Qaeav 7 01/24???" May 30, 1950 G. POUZET INSULATING HEAD FOR ELECTRIC CABLES UNDER HIGH-PRESSURE Filed April 27, 1946 2 Sheets-Sheet 2 H/w-l PRESSZ/Ef MED/UM FLO/0 Patented May 30, 1950 UNITED STATES PATENT OFF INSULATING HEAD FOR; ELECTRIC CABLES UNDER HIGH"PRESSURE Georges Pouzet, Ear-i5, France, assignor im Klempa'gnie Gvenerale DElectricite, .iaris, Erance, 'a

corporation of France Application Aprilf27, 1946', "Serial No. 6655372 TnFrance December 21,1943

(Cl. Mi k-19;)

-"i' (liaims. 1

The present invention concerns improvements "in or relating "to an 'iselatmg' head or bushing unit acwr'rlmg to my patent application Serial No. 654,988, filed March f6, 1946, for electric cati'les under pressures, in which the tightness is achieved by the combined effect of 'a resting insulation of the cable and Ufa cap resisting the pressure, and it is characterisedin'that'the is 'of 'a'special design and form which erraiiies It to'be deformed under the pressure, and nicludes one "or more joints providing the tightness, "white the continuity of tlieinsulatlon attlrepassa'ge fromthe'zone under high pressure to the zone under low pressure is secured by an insulating bushing enclosing the "cable tightly-and fitting intihe'c'ap which resists the pressure.

"In a unit of this if the pressure of the mild under high pressure attains very high vatues, the numbemf the superposed annular pieces which iorm the 1am: must be increased. For this reason, the usual pressure of the joint by means of the eapimay be insufficient to rlefor m an annular pieces, especially those of the anmlar which are tm'thest trom the cap; initial tightness of a. part of the joint is, therefore, not achieved, and the useitil efiect-of fire joint is reduced at the time of the applica- Men 'of the vhigh pressure.

in that case theqfl'astic material .tiorming the m1 pieces of must be -of .a very hard quality. alit therehtomiresults that during the mom or the zjoint lender pressure :the "annular pieces are not sufiiciently deformable at the low mines to secure .aioomplete tightness before the application :of ith'e full pressure.

invention 'aims atan improvement of the tightness act the insulating idevice accorddug in my said patent application serial No. $54,988.

lhe isolating head forming the object of the mesentiinvention and-corresponding to thatdescribed in the main patent is characterised in shat :it includes 011 the .side oDposite the [prossm'e resisting cap is. supplementary stuffing-box m- -boxes protecting the tightness.

The accompanying drawings/show two embodiments'of the invention by way of example only.

Fig. l-isa sectional view of an insulating head according-to thepresentinvention which 'is used as a terminal.

2 is-an -ex'terior view partially in section of a-housing according to the present invention tor the connection of 'two submarine cable ,por-

par'atus such as a repeater.

As illustrated in Fig. 1, 'l is the wall 'of a sleeve traversed by the cable which separates the fluid under high pressure from the space under lower pressure, 2 is the cable covered with insulation, 8 is the iconduetor of the cable, '4 is the pressure resisting eap, 5 the packing joint "com sisti'ng of super-p used annular pieces, such as described in my said -co-pending application. For reason of eleamess in the drawing the joint 3 is shown as only comprising a. restricted number ofesrmular washers;

Gap 4 is attached to wall member I by more: 38. Insulating bushing member 35 has a restr ioted portion 36 i-Lightly ire'ceived an aperture in the top -3 and in the central "bore or :cap *4. A plate member s: fits against cap t and an upwardly projecting shoulder 3! which fits within bore 34 in cap 4 and abuts the end of insulating laus-hing 35. and also has a downwardly projecting collar 33a extends into the cylindrical recess 3-2 in wall member I in which packing joint -5 is received and bears against "the latter.

In order to "facilitate a uniform *compressien of the joint 5 over its Whole height bei ore application of th'e'pr'es'sure, =-as'econ-'d joint S'such as a :stufiing lsox situated opposite the pressure resisting cap l is provided in 'a'ccorclance with the present "invention and has a portion which fits in bore 39 in wall member I. In man her, by a suitable tightening of the pressure resisting cap -4 and of "the supplementary stuffing box 6, the same initial compression is transmitted't'o the various annular pieces forming the joint.

On the other hand, in order to enable the pressing of the pieces *4 and '6 independently of each other, the annular chamber containingthe ipacking joints '5 has been illustrated as divided "by'an intermediate wall 1 serving as an abutment for the packing joints when tightening "pieces '4 and "6.

Finally, "a,CCOldiI1gtO"fihe present invention, provision is made to equip the joint on the side where the pressure of the high pressure fluid is applied, with joints providing the tightness, formed of an easily'deformable material serving to secure the tightness at low pressures until the annular pieces of the packing joint 5 of 1 material more difficult to deform, are subjected to the "effect of the full heavy pressure. 8 denotes the protective "joint intended to protest the leakage path on insulation. 9 is the protective joint intendedto'protect the-leakage path on the innersurfa'ce ofthe wall of sleeve I. "In ordertomcreasethe pressure exercised onthese protective joints when tightening of the stufiing box 6 these joints are fitted in annular metal pieces such as II], II and I2 in such a manner that the tightening of each joint is independent of the tightening of another joint.

The improvements according to the invention are not only applicable to a terminal device, such as described above, but also for the interposition in submarine cables of transducer units placed at a certain depth or on the bottom of the sea, as will be described hereinafter. In such an arrangement as illustrated in Fig. 2, I3 is the cap of the isolating head mounted on the cable I4, 15 is the cap of another isolating head mounted on the cable I6 which is to be connected to the cable l4 through an auxiliary apparatus or transducer IT. The caps l3 and I5 are fixed on the pressure resisting water tight sleeve l8 in the interior of which is placed the auxiliary apparatus or transducer. A junction box of this kind has already been described in my said co-pending application. According to the present invention, [9 and 20 are the supplementary stuffing boxes permitting homogeneous tightening of the joints 2| together with the caps l3 and I5 to be secured. 22 is the intermediate wall of the annular chamber containing the packing joints. 23 and 24 are the joints providing the tightening of the isolating head of the cable [6 intended to secure the tightness at low pressures. The cable I4 is provided with the same devices, but not illustrated.

Obviously, the supplementary stuffing boxes may assume other forms than that shown in Figs. 1 and 2, and also the design of the protect ing joints may be diiferent from that illustrated in these figures. Further, one and the same joint may serve as guard for the leakage paths on the surface of the insulation of the cable and on the internal surface of the wall of the sleeve, or several successive guarding joints may be provided, each of these joints being common or not to the leakage paths to be protected, whether fitting together or not.

On the other hand, it will be well understood that the use of the supplementary stufiing box and of the joints guarding the tightness for low pressures may, or may not be, combined.

I claim:

1. In an isolating bushing unit for an insulated electric cable traversing a wall separating a zone of high fluid pressure from a zone of low fluid pressure, a separating wall unit apertured for the passage therethrough of said cable and its insulation, said wall unit being provided with a cylindrical recess extending concentrically with said cable from the low pressure side of said wall unit a fractional part of the thickness of said wall unit and terminating in a transverse terminal inner face, a high pressure resistant cap having a central cylindrical bore, means for fixedly mounting said cap on the low pressure side of said wall unit and spacedly surrounding said cable, the top of said cap being provided with a restricted aperture of smaller diameter than its said bore for the passage of said cable therethrough, an intermediate plate member interposed between said wall unit and said cap and having a collar adapted to tightly fit into said recess and being centrally apertured for the passage of the cable therethrough, said bore of said cap being closed at one end by said intermediate plate member, an insulating bushing fitting in said bore of said cap surrounding said cable and having a portion projecting through said restricted aperture of the top of said cap to the 4 zone of low fluid pressure, a principal high pressure deformable unit fitting into said recess in said wall unit between the inner face of said recess and the end of said collar, said wall unit being provided with a cylindrical bore extending concentrically with said cable from the high pressure side of said wall unit toward but not reaching said recess in said wall unit, said Wall unit comprising an integral transverse partition separating said bore of said wall unit and said recess and having one or its faces constituting the terminal inner face of said recess, and a stufiing box mounted on said wall unit surrounding said cable and extending into said bore in said wall unit from the high pressure side thereof.

2. An isolating bushing unit according to claim 1, and an auxiliary high pressure deformable unit fitting into said bore in said wall unit between the partition inner face of said bore and said stufllng box.

3. An isolating bushing unit according to claim 1, and a low pressure readily deformable unit fitting into said bore in said wall unit between the partition inner face of said bore and said stuffing box.

4. An isolating bushing unit according to claim 1, and an auxiliary high pressure deformable unit fitting into said bore in said wall unit in engagement with the partition inner face of said bore. and a low pressure readily deformable unit fittin into said bore in said wall unit between said auxiliary high pressure deformable unit and said stuffing box.

5. An isolating bushing unit according to claim 1, and an auxiliary high pressure deformable unit fitting into said bore in said wall unit in engagement with the partition inner face of said bore, and a low pressure readily deformable unit fitting into said bore in said wall unit between said auxiliary high pressure deformable unit and said stuifing box, said low pressure unit comprising packing rings respectively engaging the bore of said wail unit and the insulation of said cable, and annular metal pieces surrounding said cable and having peripheral notches wherein said packing rings are received.

6. In a submarine cable connecting box unit, a closed box adapted to withstand high external pressure when its internal pressure is low, a pair of cable ends to be connected, electrical connect: ing means mounted within said box and connecting together the conductors of said cable ends, said box unit having two terminal separating wall units, each said separating wall unit being apertured for the passage therethrough of a said cable endand its insulation, each said wall unit being provided with a cylindrical recess extending concentrically with said cable from the low pressure side of said wall unit a fractional part of the thickness of said wall unit and terminating in a transverse terminal inner face, a high pressure resistant cap having a central cylindrical bore, means for fixedly mounting said cap on the low pressure side of said wall unit and spacedly surrounding said cable, the top of said cap being provided with a restricted aperture of smaller diameter than itssaid bore for the passage cf said cable therethrough, an intermediate plate member interposed between said wall unit and said cap and having a collar adapted to tightly fit into said recess and being centrally apertured for the passage of the cable therethrough, said bore of said cap being, closed at one end by said intermediate plate member, an insulating bushing fitting in said bore of said cap surrounding said cable and having a portion profrom the high pressure side of said wall unit toward but not reaching said recess in said wall unit said wall unit comprising an integral trans- ;verse partition separating said bore of said wall 'unit and said recess and having one of its faces constituting the terminal inner face or said recess, and a stuffing box mounted on said wall unit surrounding said cable and extending into said bore in said wall unit from the high pressure side thereof, and an auxiliary high pressure de- 1 iormable unit iitting into each said wall unit between the partition inner i'ace of said bore and said stumng box.

7. A connecting box unit according to claim 6, said electrical connecting means comprising an '5 electrical transducer for acting on the current applied thereto.

GEORGES POUZET.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 15 1,610,442 Gorton Dec. 14, 1926 1,677,126 Dennis July 1'7, 1928 2,211,122 Howard Aug. 13, 1940 2,356,351 Phillips Aug. 22, 1944 

